Do Long-term Thoracic Adaptations Occur in Pediatric Microtia Patients After Costal Cartilage Harvesting?

Abstract

Among the various reconstructive options for congenital microtia, autologous rib cartilage grafting is widely used due to its favorable long-term aesthetic outcomes. However, concerns persist regarding postoperative chest wall deformities following costal cartilage harvest. This study aims to assess long-term morphological changes using three-dimensional chest CT scans, specifically focusing on patients who have reached full skeletal maturity. A retrospective review was conducted on patients who underwent microtia reconstruction using rib cartilage graft. Only those who had follow-up CT scans taken at least five years postoperatively and were over 18 years old at the time of the scan were included. Thoracic morphology at the costochondral junction midpoint (5th~9th) was analyzed using key measurements, including transverse, anteroposterior, and sagittal dimensions, as well as Modified Haller indices. A total of 21 male patients were included, with a mean follow-up period of 101 months. In the operated hemithorax, the costochondral junction midpoint shifted medially (5th~9th), posteriorly (6th), and exhibited less descent (6th~9th) compared to the unoperated hemithorax, with significant differences (p<0.05). Additionally, the operated hemithorax had a smaller cross-sectional area than the unoperated side (5th~9th, p<0.05). While significant differences in the Modified Haller Index were noted at the xiphisternal level, differences in thoracic height were minimal. Despite perichondrium-preserving techniques, rib cartilage harvest leads to permanent thoracic asymmetry, particularly in transverse and sagittal dimensions. However, longitudinal compensatory growth appears to mitigate height differences after skeletal maturity. These potential deformities should be discussed with patients during preoperative counseling to ensure informed decision-making.